patch 8.1.1080: when a screendump test fails, moving the file is a hassle

Problem:    When a screendump test fails, moving the file is a hassle.
Solution:   Instead of appending ".failed" to the file name, keep the same
            file name but put the screendump in the "failed" directory.
            Then the file name only needs to be typed once when moving a
            screendump.

Author: brammool

src/testdir/screendump.vim

@@ -103,7 +103,13 @@ endfunc
 " Returns non-zero when verification fails.
 func VerifyScreenDump(buf, filename, options, ...)
   let reference = 'dumps/' . a:filename . '.dump'
-  let testfile = a:filename . '.dump.failed'
+  let testfile = 'failed/' . a:filename . '.dump'
+
+  let did_mkdir = 0
+  if !isdirectory('failed')
+    let did_mkdir = 1
+    call mkdir('failed')
+  endif
 
   let i = 0
   while 1
@@ -115,6 +121,9 @@ func VerifyScreenDump(buf, filename, options, ...)
     let refdump = readfile(reference)
     if refdump == testdump
       call delete(testfile)
+      if did_mkdir
+	call delete('failed', 'd')
+      endif
       break
     endif
     if i == 100

src/version.c

@@ -775,6 +775,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1080,
 /**/
     1079,
 /**/